<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		//v8引擎是单线程的js解析器
		//浏览器是多线程的

		setTimeout(function(){
			console.log(1);
		},1000)
		console.log(2);

		// 2 1
	</script>
</html>
